I got a ported box from a pawn shop today for 30 bucks. It's big and it's made out of 3/4" mdf and had an mtx terminal so i guess it could be an mtx box. I need someone to kind of guess the tuning for me...I want to put a type r 15" in this box.

17.5" deep
20" wide
15.5" tall

it has two 4"x 11" ports going up through the top.

I would like the box to be tuned to 30-35 hz. If I'm not close to this what can i do to the ports to get this tuning?

CRAZYCORNUTS18

09-11-2007, 04:14 AM

eh

Reidk

09-11-2007, 04:18 AM

well...i'm not sure what to say to that...but hopefully your working on an answer for me.

Immacomputer

09-11-2007, 11:17 AM

Are those round ports that are 4" wide and 11" deep or is it a slot port? If it's a slot port, we need to know how deep it is.

If it's round ports, it's about 2.15 cubes tuned to 47hz. If you want to use the enclosure, seal up the ports. That enclosure is useless for a 15" Type-R for a daily application.

Reidk

09-11-2007, 11:20 AM

alright how loud will the type r get in that box sealed? and is there anyway to make one of the ports longer or use the current ports to make 35 hz tuning? how long and wide would the port have to be to get the low tuning that i'm wanting?

IamDeMan

09-11-2007, 12:34 PM

alright how loud will the type r get in that box sealed? and is there anyway to make one of the ports longer or use the current ports to make 35 hz tuning? how long and wide would the port have to be to get the low tuning that i'm wanting?

Won't matter. The net volume is way less than ideal for a tuned enclosure for 15" arrrrghs. Or any 15: for that matter.

Reidk

09-11-2007, 01:57 PM

ok...answer this then. I have a maw 15 in a 2.2 sealed and it gets crazy loud (to me) will a type r 15 running off of 1000 rms get louder then the maw? And i would be blocking the ports on the ported box so the type r would be in a 2.5 sealed enclosure.

IamDeMan

09-11-2007, 02:45 PM

I couldn't really answer that as I have no technical experience with either driver. I'm guessing it would be hard to tell without a meter though lol.

Immacomputer

09-11-2007, 02:50 PM

With the enclosure sealed, the Type-R should be about as loud as the MAW and will probably get a little lower.

You're also not going to be able to mod that box to make it sound decent ported.

Reidk

09-11-2007, 04:18 PM

With the enclosure sealed, the Type-R should be about as loud as the MAW and will probably get a little lower.

You're also not going to be able to mod that box to make it sound decent ported.

allright well I'll just run it sealed then. I got two sealed boxes to choose from (if i close off the ports in the ported box).could I close one port and make the other one longer to atleast get a little bit lower tuning?

IamDeMan

09-11-2007, 04:28 PM

allright well I'll just run it sealed then. I got two sealed boxes to choose from (if i close off the ports in the ported box).could I close one port and make the other one longer to atleast get a little bit lower tuning?
You could. In fact just closing one in and of itself will produce a lower tune. I would imagine one singular 4" port will produce a lot of chuffing with a Type R though.

Reidk

09-11-2007, 05:00 PM

what is chuffing? I think that may be what my maw is doing now.

Immacomputer

09-11-2007, 06:52 PM

Having only one 4" port on a single 15" type-R will kill your output and give you a lot of port noise.

Chuffing is the onomatopoeia for the sound port noise makes. It's due to high air speed in the port which causes turbulence which is usually caused by not having enough port area. Even with two 4" ports, you would likely have port noise at high output levels. I know that my single 12 can cause a little bit of port noise with two 4" ports. Granted this is only at high volumes and around tuning but it is still there.

Even so, 2 cubes is a little small for the type-R ported. Sealed, it will be in it's max flat alignment, which should get pretty low and sound pretty smooth.